JPS6138171Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in static induction electric windings.

For example, the end of a winding to which a high voltage is applied, such as a high-voltage winding of a transformer, is close to the core yoke, so the electric field is concentrated and high stress is applied locally. Therefore, as shown in FIG. 1, an electrostatic shield 3 is often provided at the end of the winding to alleviate electric field concentration. However, if the electrostatic shield 3 is provided, the distance L from the end section 1A of the winding 1 to the core yoke 2 will need to be longer than the distance D necessary for insulation depending on the voltage by the thickness of the electrostatic shield.

Therefore, when the voltage is not so high, the electrostatic shield is omitted and an insulating layer 5 is provided over the entire surface of only the end section 1A of the coil 1, as shown in FIG. By doing so, the electric field on the insulating surface is relaxed, and the winding ends can be electrically strengthened. However, the insulation width of the end section 1A is the general section 1B,
1C..., the actual width of the end section becomes smaller than that of the general section by the thickness of the insulating layer 5. Therefore the second section 1
The electric field relaxation effect at the end a of B deteriorates, and that part becomes a weak point in terms of insulation. In addition, in this structure, the oil passage dimension S 1 between the L-shaped insulating tube 6 for protecting the winding end and the insulating surface of the end section 1A is the same as the oil passage dimension S ₁ between the inner circumference of the general section and the insulating tube 7. equal to the path dimension S ₂ . On the other hand, the dielectric breakdown electric field E of the oil pipe is higher as the oil pipe size is smaller, and is expressed as E=K·d ^- (KV/mm) (where d is the oil pipe size in mm, and K and α are constants). Therefore, the withstand voltages of end b and the general part shown in Figure 2 are approximately equal, but the electric field at the end is higher than that of the general part, so the insulation strength is weaker at the end and unbalanced. .

FIG. 3 shows that in order to improve the above-mentioned drawbacks, the width of the conductor portion of the end section 1A is made equal to the width of the general section.
In addition to increasing the shielding effect for the end section a _of
This is intended to improve the dielectric strength of the "b" portion by reducing the . However, this structure has the disadvantage that the oil passage is narrow, resulting in poor oil flow and poor cooling of the windings.

The present invention has been devised in view of the above points, and an object of the present invention is to provide a stationary induction electric appliance winding that can strengthen the end insulation without impairing the flow of oil at the end of the winding.

An embodiment of the present invention will be described below with reference to the drawings. As shown in Fig. 4, the present invention is to divide the end section 1A of the winding 1 into a conductor group 1A ₁ whose inner diameter matches the inner diameter of the general section and a conductor group 1A ₂ whose outer diameter matches the outer diameter of the general section. In addition to being separated in the direction, an insulating layer 5 is provided on the entire surface of the inner and outer conductor groups 1A ₁ and 1A ₂ , respectively, and an oil pipe 8 is formed between both conductor groups. The structure of other parts is shown in Figures 2 and 3.
This is the same as the conventional winding shown in the figure.

With such a configuration, the shielding effect of the end section 1A against the end "a" of the second section can be enhanced, and the shielding effect between the insulating surface of the end section 1A and the L-shaped insulating tube 6 can be increased. The oil pipe dimension _S1 is also reduced, making it possible to increase the insulation strength of the "b" section. Further, since the oil for cooling the windings flows through the oil passages 8 of the conductor groups 1A ₁ -1A ₂ of the end section 1A, sufficient cooling can be expected. Note that since the outside of the conductor group 1A ₁ and the inside of the conductor group 1A ₂ have approximately the same potential, almost no electric field is applied to the oil pipe 8, and it does not become a weak point in terms of insulation.

As described above, according to the present invention, the end section is divided into a conductor group whose inner diameter is the same as the inner diameter of the general section and a conductor group whose outer diameter is the same as the outer diameter of the general section, and the surfaces of these conductors are insulated. By providing a layer and an oil passage between the two, the end insulation is strengthened without impairing the cooling of the winding, and the insulation distance between the winding end and the core yoke is also reduced, making it economical. A winding wire with excellent insulation properties can be obtained.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing different examples of conventional static induction electric windings, and FIG. 4 is a cross-sectional view showing one embodiment of the static induction electric winding according to the present invention. 1...End section, _1A1 , _1A2 ...Conductor group, 5...Insulating layer, 8...Oil pipe.

Claims (1)

[Scope of utility model registration request] In a stationary induction electric winding in which a plurality of coil sections each having a conductor wound in a disc shape are arranged in the axial direction, the end section is radially divided into a conductor group whose inner diameter is the same as the inner diameter of the general section, and a conductor group whose outer diameter is the same as the inner diameter of the general section. A stationary induction electric winding characterized in that it is separated into conductor groups having the same diameter as the outer diameter of a general section, an insulating layer is provided on the surface of each of the separated conductor groups, and an oil path is provided between them.